Shared hosting are cheap, but normally they don’t allow us the use some kind of features. For example we cannot see the error log. That’s a problem when we need to see what happens within our application. Normally I work with my own servers, and I have got full access to error logs. But if we cannot see the error log and the server is configured with display errors = off in php.ini (typical configuration in shared hosting), we have a problem.

His solution involves an "error sniffer" script that captures the issues in a script and echoes them out at the end. In his ErrorSniffer he sets up a custom error, exception and shutdown handler to grab the problems and capture them for later use - including echoing them out to the user if desired.